Many digital electronic systems, including computer systems, include more than a single device. The multiple devices within a system may be coupled to each other by way of interconnects. One type of interconnect may be based on serial data delivery from a transmitting device to a receiving device.
The purpose of an interconnect is to transport data reliably from one point to another. For reliable re-construction of data, the timing reference, i.e. clock edge positions, used by the receiving device should resemble the timing references used at the transmitting device.
One of the most commonly used receiver architectures for high-speed serial data transmission is based on recovering a clock embedded in the received data by tracking the phase of that received data. High data rates mean the receiving devices need to operate within shrinking timing windows and therefore requiring accurate phase tracking.